You'd think that taking a screen shot would be easy... but no, not if you want to have the game UI visible. 
Basically the UI get's rendered some time after the camera considers rending is complete so you have to use a co-routine to get the screen shot function to fire at the right time....
This is another "dave won't remember this if he doesn't write it down" post.

Unities UI is designed to scale to handle different resolution screens. This is great but you probably want the UI to look at at the intended resolution rather than looking good in the scene editor.  To preview the UI while designed it at the intended resolution (in my case 1080p) you can set it thus:

Of course thenthe UI looks ugly in the scene editor because it's scaled but.. le sigh....I guess tweak the window size to get 50%.

Unity has this concept of Camera Depth.  It's got nothing to do with the zbuffer, it's the order that the cameras get rendered if you have more than one camera active.   Somehow my main game camera got set to a camera depth of -1 when I added another camera which meant that even if it was the only camera active it didn't get rendered.  So that's an hour I can never have again. 
If your camera mysteriously stops working despite the fact you can see it working just fine in other camera views...  this could be your problem. 

https://answers.unity.com/questions/418471/camera-preview-is-okay-but-game-view-is-not.html

You'd think that making the camera frustum visible in the scene editor would be simple but it's not.
Here is a work around.

• Select the camera you want to look through
• Lock the inspector (this will mean Unities camera preview stays visible)
• Add another inspector tab to edit objects with

Tip from:  https://gamedevworks.com/blog/unitytips-lock-camera-preview-window/

This is another "Dave won't remember this if he doesn't write it down" post.

I'm building out a tiled level in Blender for export to Unity.  I have a series of tile components and I want to texture them in Substance but I need the textures to match with regard to density and scale.  I found a trick for this.  If I select all three objects and go into edit more, I can select all the UV coords and do a Smart UV Project.  This means all 3 tiles share the same texture but also means they are scaled consistently. The only problem I found was that smart project sometimes rotates faces to pack the UV map.  My solution to this was to use masking in Substance to get the fill layer textures to match.  It's not perfect, but its better than trying to get the faces to scale manually across multiple UV sets.

Here you can see in substance I used layer masks to all for rotating the brick texture to match the UVs.  Getting the final alignment with the offset tool was a bit tricky, but it works.

This is another "Dave won't remember this if he doesn't write it down" post. 

I had weird cracks in my Shadows.

Reducing Bias and Normal Bias appear to fix or reduce this... and I don't have time to read up on why... 

This is another one of those if I don't write it down I won't remember posts... because I have a memory like a goldfish.  Here's the fix... and the credit.... 

How to get Unity text mesh pro (tmp) objects to render last or without clipping for HUD elements.
TBF, I'm not really sure what TMP is doing and I don't really care, but changing the shader seems to do what I want.  This is the right shader on PC.  For some reason my project defaulted to a different one.
This is another "Dave made a blog post because he'll forget if he doesn't write to down" blog post.